Saturday, April 2, 2016

Global Star Party April 2nd

Live Jupiter special!

It was a beautiful night in Melbourne, then about 10:30 just half an hour before "go-live" the clouds came from nowhere. Fortunately they didn't hang around for long - it must have been a moment of climatological rebellion with the impending ending of daylight saving several hours later.

It was a little bit sad that the Great Red Spot had already transited before we got to air - but I did get some great footage of it before the clouds swept in. By the time we were on air the clouds had cleared and we continued on with the "boring side of Jupiter".

I have been in a number of virtual events usually with my DSLR plugged directly into the laptop and screen sharing the Cannon EOS utility and using live view. The best method of course is a astronomy camera in a web cam setup. On this occasion I tried something a little different. Using the iPhone 6 and an eyepiece adapter, a 25mm eyepiece and the 645 App I was able to take some of the light of Jupiter out (its usually too bright to see any detail on the disk) by taking the ISO to 32 and setting the exposure time to 1/100 of a sec and the through the lens view adjusts to a "what you see is what you get" view. Then sharing that back to my MacBook using reflection, I was able to then screen share the Reflection App into the Google Plus Hangout. Pretty cool!

14inch Smart Dobbie>Barlow>25mm Plossl Eyepiece>Smart Phone Telescope Adapter>645 Pro [Application]>ISO 32 & 1/100 Settings>Reflector to MacBookAir>Reflector Screen record.

An excellent result, but more essentially here, what astronomy can we do with using equipment that we already have or that's relatively inexpensive, but easily accessible.

Thanks to the Global Star Party for hosting me on the show!

Monday, March 14, 2016

Jupiter Mar 13th 2016

Finally got some time on Jupiter tonight. I'm still not much of a planetary photographer but managed a nice single frame on my smart Dobbie and Cannon 550D. Io, Ganymede and Europa (Left>Right)

Also still playing with the Star Analyser on the iPhone. Interesting you can actually see the separate spectra of the moons. (note the different position angle due to a different camera and lens setup).

As its a long weekend its fun to have a bit of a play around with cameras, lens and such.

Here is the separated spectra, and bearing in mind here they were very faint and I am really just practicing technique here and having some fun - but you can tell some differences.

Io

Jupiter

Ganymede

Europa

Each was separated out in a thin slice and then had the vertical height changed to highlight the various light levels.

Friday, March 4, 2016

Periodic Comet P/2016 BA14 (PANSTARRS)

Discovered recently by the PANSTARRS survey, P/2016 BA14 will set a record for the third closest approaching comet of all time on March 24th. It will brighten from its current magnitude of 18 to about Mag 13. Sadly, it will pass outside Earth's orbit so there shouldn't be any meteor shower activity as the tail (what there is of it - not much as you can see) will be pointing away from us from what I can tell from the orbit diagram.

What I find most fascinating about this object, is that it crosses the plane of the solar system, very near earth, almost at its perihelion. Also of interest is the periodic comet 252P/Linear which has a very similar orbit. The super sleuth astronomer detectives will be onto that, I'm sure. Of course I'm not qualified to comment on such things, but I'm thinking .... Hhhmm ...If two asteroids departed the plane of the solar system from a point "near Earth", did something happen to them if they were both there at the same time. Yes I know, we are talking comets here and comets normally come from the Oort Cloud at any angle, but its really interesting to contemplate. Am I allowed to call "dibs" for a future PHD that I may get around to doing one day ;-)

That's why science is so much fun, you get to ask questions like that and go and work it out.

Tonight's data:
COD Q62
OBS P. B. Lake
NET PPMXL
PK16B14A C2016 03 03.43620 05 51 24.42 -34 16 10.7 18.4 N Q62
PK16B14A C2016 03 03.43801 05 51 24.54 -34 16 08.7 18.3 N Q62
PK16B14A C2016 03 03.43976 05 51 24.62 -34 16 06.7 18.5 N Q62
PK16B14A C2016 03 03.44150 05 51 24.72 -34 16 04.9 18.4 N Q62
PK16B14A C2016 03 03.44324 05 51 24.83 -34 16 02.8 18.2 N Q62
PK16B14A C2016 03 03.44498 05 51 24.95 -34 16 01.1 18.3 N Q62
PK16B14A C2016 03 03.44672 05 51 25.05 -34 15 58.9 18.2 N Q62
PK16B14A C2016 03 03.44860 05 51 25.15 -34 15 56.9 18.3 N Q62
PK16B14A C2016 03 03.45035 05 51 25.26 -34 15 55.1 18.3 N Q62
PK16B14A C2016 03 03.45209 05 51 25.35 -34 15 53.2 18.2 N Q62
PK16B14A C2016 03 03.45383 05 51 25.47 -34 15 51.0 18.3 N Q62
PK16B14A C2016 03 03.45557 05 51 25.57 -34 15 49.2 18.4 N Q62

Looking forward to a nice telescopic show late in the month whilst we are at NACAA.

Thursday, February 11, 2016

The Spectre of the iPhone Spectroscope

UPDATE: Feb 27th 2016 I have got them calibrated now. The iPhone6 version calibration is still a bit rough. Lining up on the Helium Lines seems to produce the best results. The camera response is markedly different for the iPhone over the Cannon 550D. Now that I know what we are looking at here, next time I image I can make sure I get the image in a bit better focus. I have also found a way to reduce camera shake by delaying the shutter open until 3 secs after you press the shutter button. Whilst you can see visually the same lines, when extracted using Visual Spec the camera response seems a bit different.

UPDATE: Feb 22nd 2016 Well here is the comparison - again I am still very new at this and am still learning how to properly calibrate the specturm.

Colour, the final frontier. Of course if you want to be a "real astronomer" the visible spectrum is only a small part of the story. Much of our knowledge of astronomy comes from spectra and radio astronomy.

At the 2014 NACAA Conference I was drooling over Ken Harrison's amazing Spectroscopes after his talk and made the comment, it would seem so unfair to buy one off the shelf without going through the pain [Learning Experience] of trying to build one myself. So true to my word I had a go at the basic process of "getting colour".

I wasn't too concerned at this stage about quality, just some rational experimentation with the process to gain a deeper understanding. So I went off to the local hardware and bought a few bits and pieces and broke up a cd (carefully) and peeled the film back. At this stage it was unclear to me whether Barry Manilow CDs or Justin Beiber CDs would provide the best high or low resolution diffraction grating. Carefully pulling apart a three blade razor and using two of them to create a slit, challenged my dexterity. After tinkering away for a couple of sessions over a few weeks, I managed to come up with this monstrosity. Splits the light, can see colour, but probably absolutely useless for real science, but fun to play with and demonstrates the principle of a spectroscope well.

The first place to start this journey is with Ken Harrison's book Astronomical Spectroscopy for Amateurs. It is well written but looks quite daunting when you first pick it up. However if you work through it bit by bit, its a great book with everything you need to know.

Feeling a little more confident, I invested in the next logical step - a Star Analyser 100. This is the entry level standard for beginners, and produces fine results as we'll see.

After passing it around the family to have a look at the cool effects looking at the ceiling lights, I lost the plot and departed from Ken's careful, meticulously presented steps, with the outrageous thought - I wonder how this baby would go on an iPhone! I am constantly amazing at STEM events and star parties how the "younglings" immediately are so amazed by what they see through the eyepiece they want to whip out the smartphone and take an image home with them.

Surely it couldn't possibly work. After all the iPhone 6 sensor is only 4.8mm by 3.6mm, it has a focal length of 29mm and is f2.2. But its an 8M pixel camera (said my evil twin subconscious), your Fingerlakes PL11000M is only 11M pixels so its only 3000 less pixels, how bad could it be....hang-on whats the pixel size ...ah 1.5um versus 9um, interesting. So the sensor is 3264 x 2448, interesting ..... iPhones do take good photos......on a sunny day.....not in the night sky. This went on for a while!

So in the end there was nothing else to do but try it, and learn from your spectacular mistakes!

The next problem was how do I keep the shutter of the iPhone open for long enough to take star photos on a guided telescope - this is not the moon, a great iPhone target normally, but with the standard phone settings thats all the iPhone seemed good for. So channeling my teenagers I thought, there must be an app for that. To my amazement I could not only find one, there was a choice of several apps and 645 Pro could even do it with an Kodak Ektrachrome 64 film "feel to it". NOTE: to those born after the 90's, can you imagine only getting 36 images on one roll of film and not being able "to delete the bad ones" until after you had paid $25 and sent it off to the developers and had it returned to your letter box. In those days the lens ONLY pointed away from you - THE HORROR! Anyway I digress. 645 Pro basically turns your iPhone into a simulated DSLR and enters the workflow of the photography before any JPEG compression. You can set ISO and shutter speed, bracket exposures do all sorts of things that you can do on a DSLR.

With my trusty new app, my camera adapter, my star analyser, a 25mm eyepiece, I was ready for action.

I started on Canopus, after the bright star align was completed, but was more interested in Betelgeuse. After slewing and removing the eyepiece and inserting my newly built contraption, I was sure it was the world's first ultra-low resolution Spectroscope. A quick google search showed I was in fact two years behind the times. However to my amazement I had colour and with some detail, I got "lines" as well. I messed around trying different settings and moved over to Betelgeuse and took some more and put the 2 x barlow in front of the Cannon 550D and tried that for comparison purposes. (See image - top of page)

As an experienced "normal" (although I know you are wondering by now how "normal" that is) astrophotographer I was keen not to overexpose the image - Hmmmm - I have no idea what the well depth of an iPhone sensor is, lets just take as many as we can and see how we go.

I must say the results amazed me. Punching the air in victory, my evil sub-conscious dredged up an "I am invincible" [from the Bond film Golden Eye].

By now it was approaching midnight, and quietly tiptoeing around my back yard I packed up the telescope and headed inside. Damn ... I was so excited, I forgot to change the camera settings to save in dRAW/TIFF - back to the drawing board! Well at least I have some nice completely useless JPGs, but what an exercise that was, one I know I will be able to use again and again.

Friday, February 5, 2016

Certain of uncertainty for near earth asteroids

In my continuing efforts to de-mystify the art of Asteroid Astrometry, I thought I'd follow up last week's article on about 2016 BE with a deeper examination of the Uncertainty parameter when its listed in orbital elements.

This week there is some attention on 2013 TX68 which will possibly make a record close pass of 11,000 klms or possibly be 40 times further away than the moon on March the 5th. I can see that puzzled look on your face ;-) 2013 TX68 is also a Virtual Impactor in 2017, a term we discussed last week.

So firstly lets get some perspective on this uncertainty thing.

2011 CF66 was also listed as a virtual impactor for Feb 2nd 2016, it didn't hit us, no-one was worried if it would, and in fact no-one has any idea where it actually is. It is only a tiny asteroid about 3-9m in diameter and wouldn't have done any damage even if it did. In fact there are 20 other virtual impactors listed in the Risk Table this year, the next one might approach on Feb 18th, is 2009 VZ39, and is slightly smaller than 2013 TX68. 2009 VZ39 is also in the daytime sky and not observable for follow up and further confirmation. I only highlight this to emphasise the point here - all asteroids once they are discovered need to be tracked for sometime, to improve the precision of the orbit before any pronouncements about where they are going to be at a certain point in time. The difference between 2013 TX68 and 2009 VZ39 for example is that 2013 TX68 was observed for 31 data positions (astrometry) over 3 nights where as 2009 VZ39 was observed on only one night with 8 astrometric data positions. If you look at the orbital elements for 2013 TX68 the uncertainty parameter is listed as 7, where as for 2009 VZ39 there is not even enough data to start that calculation. For 2011 CF66, there is a 1.1e-8 chance of a collision between 2016 and 2114, so its mathematically possible, but highly unlikely.

NASA/JPL produced this nice graph with it's press release this week which illustrates the point well.

Image Credit: P. Chodas (NASA/JPL)

What you see is a graphical representation of the "error bars" or the zone of uncertainty, based on the orbit elements that we currently know. This asteroid will be picked up again in future surveys and the zone of uncertainty will reduce further.

Uncertainty Parameter is quite a complex calculation, but it essentially always starts off being a "9" and reduces over ensuing months as more data is collected. Uncertainty is a table of the "Runoff" of arcsecs per decade and Level 7 just means essentially there will be less than 33,121 arcsecs of "runoff" over the next decade. You can think of this as being: in a decade the place to look will be 33,121 arcsecs bigger than the range of uncertainty we need to factor in when we look for it now.

Many of the "click-bait" bloggers and conspiracy theory followers regularly confuse Uncertainty with the Torino Scale - they shouldn't, as even WIKIpedia has a great explanation of the Uncertainty factor, however they google "Asteroid rating 7" and get a hit on what the Torino Scale is and confuse the two, without doing any further investigation. The Torino scale is a risk weighted table and ALL current Virtual Impactors are listed as Torino Level 0. The virtual impactors that are listed have "potential" collisions over a range of years and are only there because we largely don't have enough data yet to remove them.

Asteroid Apophis (99942) 2004 MN4 briefly shot up the Torino Scale to a record high Level 4, before subsequent radar imaging and 4452 observations over 10 oppositions reduced its Uncertainty Parameter to 0 and its Torino Level to 0, with an asterisk that it needs to be carefully watched. Asteroid Apophis will be a naked eye object on April 13th 2029 when it makes a very close but HIGHLY CERTAIN pass of the earth. This level of certainty is only refined by many hundreds of hours of dedicated work from professional and amateur astronomers.

Lastly, Uncertainty should not be confused with don't know, don't care, have no idea what we are doing. Its just a case of not YET having enough data, more needs to be collected.

Friday, January 29, 2016

Asteroid 2016 BE Virtual Impactor for now in 2053

UPDATE 31/1/2016: The 2053 pass has been eliminated as a risk. There are still 5 virtual impacts from 2076 - 2111. These will also likely be removed as the precision of the orbit is improved.

Tonight, tracking potential virtual impactor Asteroid 2016 BE. Its a 79m wide Asteroid discovered on Jan 16th by the Catalina Sky Survey(703).

78 positions have so far been reported from 18 different observatories, including both H06 and I89, the iTelescope.net observatories. I managed to grab another 3 positions tonight. The asteroid is starting to speed up (in terms of relative velocity against the background stars) and tonight is moving quite quickly at 19 Arcsecs per minute. As a result of the fairly bright magnitude and the fast speed, you need to take as short an exposure time as possible. However the full moon is still pretty bright I had to use 30 sec images which means the asteroid is still slightly streaked. I have used a stacking technique to make sure my residuals are still reasonably good (given it is travelling at fairly high speed).

So what actually is a "Virtual Impactor". As asteroids are tracked the length of the recorded "arc" increases - now 10 days for 2016 BE. Of course the level of precision for future positions of the asteroid increases the longer the "known arc" and therefore the ability to determine future positions of the asteroid improves as the "zone of uncertainty" reduces. As long as the "zone of uncertainty" overlaps the earth's future orbit position, the object is listed as a virtual impactor for that pass. This happens from time to time without much concern, because as the precision of the orbit improves with more observations, the object usually drops out of the risk table quite quickly.

Whilst the asteroid will make a moderately close pass in the first week of February at 5.7 Lunar distances, its important to understand that the "virtual impact" currently listed in the Sentry Risk Table is for the 3rd February 2053 .... NOT ON THIS PASS!!!! As you would expect the "zone of uncertainty" for 2053 is much large than the "zone of uncertainty" for next week. So it will take many further observations before it is (most likely) removed from the risk table. Its current risk table score of Torino-0 just means that at this point the chance of a collision in 2053 has not been able to be eliminated at this stage.

Measured position:

K16B00E KC2016 01 28.46044 12 04 01.15 +65 50 49.0 16.9 R H06

K16B00E KC2016 01 28.46319 12 04 09.44 +65 49 54.8 17.3 R H06

K16B00E KC2016 01 28.46604 12 04 18.01 +65 48 58.7 17.4 R H06

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